Breast cysts and aluminium-based antiperspirant salts Article Published Version Creative Commons: Attribution 4.0 (CC-BY) Open access Darbre, P. (2019) Breast cysts and aluminium-based antiperspirant salts. Clinical Dermatology: Research and Therapy, 2 (1). 128. Available at http://centaur.reading.ac.uk/88553/ It is advisable to refer to the publisher’s version if you intend to cite from the work. See Guidance on citing . Publisher: Scientific Literature All outputs in CentAUR are protected by Intellectual Property Rights law, including copyright law. Copyright and IPR is retained by the creators or other copyright holders. Terms and conditions for use of this material are defined in the End User Agreement . www.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading Reading’s research outputs online Clinical Dermatology: Research And Therapy Special Issue Article “Breast Cyst” Research Article Breast cysts and aluminium-based antiperspirant salts Philippa D Darbre* School of Biological Sciences, University of Reading, UK ARTICLE INFO ABSTRACT On the basis that aluminium-based antiperspirant salts are designed to block apocrine Received Date: July 17, 2019 Accepted Date: September 23, 2019 sweat ducts of the axilla, and that breast cysts result from blocked breast ducts in the Published Date: September 30, 2019 adjacent region of the body, it has been proposed that breast cysts may arise from KEYWORDS antiperspirant use if sufficient aluminium is absorbed into breast tissues over long-term usage. This review collates evidence that aluminium can be absorbed from dermal Aluminium application of antiperspirant salts and describes studies measuring levels of aluminium Breast cancer Breast cysts in breast tissues, including in breast cyst fluids. It is notable that breast cysts, as for Antiperspiran breast cancers, start most frequently in the upper outer quadrant of the breast, which is the region closest to the site of underarm antiperspirant application. Mechanistic Copyright: © 2019 Philippa D Darbre evidence is reviewed for a link between aluminium levels in breast tissue, cyst et al., Clinical Dermatology: Research And Therapy. This is an open access formation and development of breast cancer. If excessive use of antiperspirant is a article distributed under the Creative cause of breast cysts, then reduction or cessation of use could provide a preventative Commons Attribution License, which or even treatment strategy. Furthermore, if cyst formation from antiperspirant use is permits unrestricted use, distribution, an indicator of increased risk for breast cancer, then reduction in use of antiperspirant and reproduction in any medium, provided the original work is properly could also provide a strategy for reducing breast cancer risk. cited. INTRODUCTION Citation for this article: Sudarshan Cystic disease of the breast is a common benign disorder of breast biology which Khokhar, Sourabh Verma, Chirakshi results from blockage of breast ducts and is classified according to the size of the Dhull. Breast cysts and aluminium- cysts formed [1]. If the cysts are small and typically visible only by microscopy, the based antiperspirant salts. Clinical Dermatology: Research And Therapy. condition is termed “microscopic cystic disease”. Due to the small size of such cysts, 2019; 2(1):128 diagnosis is usually only made when there is another lesion present and therefore the frequency and significance of microscopic cysts remain largely unknown. When the cysts are palpable and over 3mm in diameter, the condition is termed Gross Cystic Breast Disease (GCBD). The larger size of the cysts enables them to be clinically diagnosed and GCBD has been reported to occur in up to 7% of women living in western countries [1]. This makes GCBD the most commonly diagnosed benign breast disorder [1,2]. Although not life-threatening in itself, development of cysts causes anxiety, and treatment is invasive. GCBD arises from dilation and/or obstruction of ductal terminal lobular units (Figure1) which, due to retention of fluid, then swell up to Corresponding author: form fluid-filled sacs [1,2]. Although gross cysts are known to be associated with Philippa D Darbre, retention of fluid and secretory material linked to the metabolic activity of the lining School of Biological Sciences, University epithelial cells [1,2], the molecular basis of cyst formation and the reasons why cysts of Reading, Hopkins Building, Reading, RG6 6UB, Tel: + 44 118-378-7035, arise so frequently in western women remain to be identified. Aluminium-based salts UK, are used as the active antiperspirant agent in underarm cosmetics to reduce sweating Email: [email protected] in the underarm area [3]. The main salts used are aluminium chloride, aluminium 01 Breast cysts and aluminium-based antiperspirant salts. Clinical Dermatology: Research And Therapy. 2019; 2(1):128. Clinical Dermatology: Research And Therapy chlorohydrate and aluminium zirconium chlorohydrate glycine aluminium is absorbed into breast tissues [4-6]. Since complexes [3]. Their mechanism of action is thought to involve antiperspirant salts are applied frequently to the underarm the formation of a physical plug at the top of the sweat ducts region and left on the skin, this allows for a continuous dermal which is composed of a mixture of damaged cells and exposure which could result in absorption of aluminium and precipitated aluminium salts [3]. This plug then prevents the deposition into underlying breast tissues. This might then give escape of sweat onto the skin surface which would otherwise rise to subsequent blockage of breast ducts if sufficient generate odour from bacterial action on the sweat as it lingers aluminium were absorbed or accumulated over long term on the skin. On the basis that antiperspirant formulations are usage. Aluminium complexes have been previously linked to the designed to block apocrine sweat ducts of the axilla, and that development of granulomas at the site of antiperspirant breast cysts result from blocked breast ducts in the adjacent application [7,8] and the use of aluminium-based vaccines is region of the body (Figure1), it has been hypothesised that also known to cause itching nodules locally at the site of breast cysts may arise from antiperspirant use if sufficient vaccination [9,10]. Figure 1: Structural features of the human breast showing the sites of breast cyst formation. The human breast is composed of a series of ducts and lobules which are lined with epithelial cells and are embedded in fatty stromal tissue. It is the lining epithelial cells which produce the milk which then flows down the ducts to the nipple. Breast cysts result from blocked ducts in the ductal terminal lobular units indicated in pink. Aluminium-based antiperspirant salts are used to block sweat ducts in the underarm region (indicated in blue): if sufficient aluminium were absorbed over time, could the breast ducts not also become blocked by the same mechanism? 02 Breast cysts and aluminium-based antiperspirant salts. Clinical Dermatology: Research And Therapy. 2019; 2(1):128. Clinical Dermatology: Research And Therapy DERMAL ABSORPTION OF ALUMINIUM FOLLOWING 1.81g/cm2 for intact skin but this was increased to UNDERARM APPLICATION OF ANTIPERSPIRANT 11.5g/cm2 for stripped skin [14]. The Cosmetics Directive of In 2001, a report was published by Flarend and colleagues the European Union [15] recommends that these aluminium salts which demonstrated the principle that aluminium could be taken should not be applied “to irritated or broken skin” which up through the skin following application of antiperspirant to conflicts with these current practices of shaving prior to the human underarm [11]. In this study, an antiperspirant antiperspirant application and therefore ignores the regulatory formulation was applied which included the 26Al isotope and advice [15]. Furthermore, recent calculations by the BfR in thus allowed aluminium to be traced from application to the Germany estimate that antiperspirant use, in conjunction with human underarm into blood and urine [11]. Conclusions from prior shaving, may result in absorption of aluminium at levels this research were that aluminium uptake from a single exceeding tolerable weekly intake guidance, and accordingly application was small [11], but long-term effects of low-dose women have been advised in their report not to shave prior to uptake have yet to be studied. This is pertinent to breast tissue antiperspirant use [16]. in particular because this is the site adjacent to antiperspirant MEASUREMENT OF ALUMINIUM IN BREAST CYST FLUID application and also because breast tissue contains high levels Aluminium plays no known functional role in biological systems, of calcium phosphate which would generate a favourable but due to the activities of man [17], increasing levels of this chemical environment for aluminium deposition. In 2004, this non-essential metal are being found in biological tissues [18]. was followed by a clinical case report documenting The source of the aluminium cannot be specifically identified in physiological consequences following absorption of aluminium such measurements because the human population is now from use of underarm antiperspirant [12]. Uptake of aluminium exposed through diet, vaccines and antacids as well as through in a human subject was measured as rising to 4M in the blood antiperspirant use [6]. However, research has identified following the underarm antiperspirant use, and this was aluminium as now